Inflammatory bowel disease (Crohn disease): Clinical sciences

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Introduction0:00–0:43

Inflammatory bowel disease, or IBD for short, is a condition characterized by chronic gastrointestinal tract inflammation that can be subdivided into Crohn Disease and Ulcerative Colitis.
Crohn Disease, or CD, can affect any part of the GI tract, mouth to anus, and is characterized by transmural skip lesions, which can lead to abdominal pain, diarrhea, fatigue and fever.
Management is based on the severity of disease and it can be categorized as mild to moderate, moderate to severe, or severe.

Unstable Patients0:43–2:32

Now, when evaluating a person with suspected CD, you should first perform an ABCDE assessment to determine if they are stable or unstable.
They might present with signs of shock like tachycardia and hypotension. Because of the high mortality-risk in these individuals, it is essential to hospitalize them, obtain intravenous access, and start them on IV fluids.
Once they are stable, you should determine the cause of their instability, which can be small bowel obstruction, or SBO for short, or sepsis.
Alright, individuals with SBO typically report severe nausea, vomiting, and the absence of flatus, while physical exam might reveal a distended abdomen and high pitched, tinkling, bowel sounds.
An abdominal X-ray will show dilated loops of small bowel with air-fluid levels. Now, when it comes to individuals with sepsis, which often occurs from an abscess, they might report fever, fatigue, localized pain and sometimes a mass in the perianal area.
On a physical exam, you might be able to palpate an abdominal or perianal mass, but sometimes you’ll need to use a CT or MRI of the abdomen and pelvis to detect the abscess.
As for the treatment, all unstable individuals should be hospitalized, get IV antibiotics and a surgery consultation for laparoscopy or abscess drainage.
Additionally, for an SBO, you should place a nasogastric tube for suction. Ok, let’s switch gears and talk about stable individuals.

History & Physical, Stool studies, Labs2:32–4:27

The first step is to obtain a focused history and physical exam. History typically reveals postprandial abdominal pain, usually in the right lower quadrant, and non-bloody diarrhea.
However, if the disease is in the colon, the patient might report bloody diarrhea. Additionally, they may report fatigue, weight loss, and fever, as well as extraintestinal manifestations such as joint or eye pain, skin findings like tender red spots that indicate erythema nodosum and painful ulcerations associated with pyoderma gangrenosum.Now, since CD is transmural inflammation, some individuals develop penetrating and stricturing disease.
This can lead to complications such as strictures, fistulas, phlegmon, or abscesses. If there are complications, a physical exam usually reveals a tender abdomen and sometimes a palpable abdominal or perianal mass, from stricture or an abscess.
Additionally, a skin exam might reveal fistula tracts.Alright, to differentiate IBD from other diagnoses with similar presentations, such as Irritable Bowel Syndrome or C.difficile colitis, you should obtain stool laboratory studies.
Fecal calprotectin is a marker of colon inflammation. Since IBS does not cause colon inflammation, having a positive fecal calprotectin would increase our suspicion for IBD.
Similarly, negative stool studies for infectious microbiology help rule out C.difficile colitis. Next, you should check blood work, which may reveal anemia, dehydration, malnutrition, and elevated inflammatory markers such as ESR and CRP.

Ileocolonoscopy with biopsy and MRE4:27–6:05

If the H&P, stool study, and lab findings suggest IBD, the next step is to confirm the diagnosis with an ileocolonoscopy with biopsy.
You may observe discontinuous deep linear serpiginous ulcerations, which usually skip the rectum but commonly involve the ileum and cecum.
Typical biopsy findings of CD include transmural chronic inflammation with granulomas. In addition to endoscopy, a person with suspected CD should have a magnetic resonance enteroscopy, or MRE for short, to evaluate their small bowel.
An MRE can reveal bowel thickening from strictures, organ connections from fistulas, and mesenteric fibrofatty proliferation, also called creeping fat.
Finally, if they have symptoms such as colicky abdominal pain with nausea, vomiting, or anorexia, an esophagogastroduodenoscopy, or EGD, should be used to check for upper gastrointestinal involvement.
Once you’ve confirmed the diagnosis of CD, you should determine its severity based on signs and symptoms such as abdominal pain, presence of bloody diarrhea, nausea, vomiting, weight loss, anemia, presence of complications, and how much CD impacts quality of life.
Using these findings, CD can be subdivided into three main categories: mild to moderate, moderate to severe, and severe.
Alright, let’s talk about individuals with mild to moderate CD. This typically presents with symptoms that minimally affect their quality of life, such as mild abdominal pain, diarrhea, and minimal weight loss, less than 10 percent of their body weight.

Mild to Moderate CD6:05–8:16

They typically won't report nausea, vomiting, or fever, and their diagnostic work up is negative for anemia, dehydration, malnutrition, or complications associated with CD.
Now, when it comes to treatment, the goal is to induce remission, using induction therapy which differs based on the area of the GI tract involved.
Ok, starting with right-sided ileocecal disease, induction therapy begins with the corticosteroid budesonide as first line therapy.
Budesonide can be taken orally, but it’s minimally absorbed until it reaches the ileocecum, where it acts locally. If this induces remission, the management changes to maintenance therapy, which is used to keep the person in remission.
Maintenance therapy involves tapering off budesonide and starting methotrexate, or a thiopurine immunomodulator such as azathioprine.
You should schedule a follow up in 6-12 months to check for continued remission. This is done through clinical evaluation and repeated ileocolonoscopy with biopsies.
Now, if you are unable to achieve remission with budesonide, you should switch to moderate-severe CD treatment.Next, let’s discuss the individual with primarily colonic involvement.
You should initiate induction therapy with an oral 5-aminosalicylate, or 5-ASA, such as sulfasalazine. If this achieves remission, continue the oral 5-ASA and re-evaluate clinically and endoscopically in 6-12 months.
However, if the oral 5-ASA induction therapy doesn’t induce remission, switch to moderate-severe CD treatment. Let's move on to individuals with moderate to severe CD, whose symptoms usually have a greater impact on their quality of life.

Moderate to Severe CD8:16–9:44

They often report frequent diarrhea, significant weight loss, intermittent nausea and vomiting, abdominal pain, and fever.
Lab results may reveal anemia, dehydration, and malnutrition. When it comes to treatment, individuals with moderate to severe CD are started on oral systemic corticosteroids, such as prednisone; and a monoclonal antibody, like infliximab.
These can be combined with an immunomodulator, such as 6-mercaptopurine, or 6-MP for short. If the patient achieves remission, taper off the corticosteroids and continue the current medical therapy.
Remember to follow up in 6-12 months.On the other hand, if there’s no remission, continue oral systemic corticosteroids and add an immunomodulator if they are not already on one.
If they are already on an immunomodulator, switch to a different monoclonal antibody, like adalimumab. If this achieves remission, taper off the corticosteroids, continue the current medical therapy for maintenance, and follow up in 6-12 months.
Finally, if the second induction attempt doesn’t achieve remission, switch to severe CD treatment. Finally, individuals with severe CD, often referred to as fulminant CD, require hospitalization because their quality of life is greatly impacted by symptoms like persistent vomiting, weight loss to the point of cachexia, high fever, and severe abdominal pain.

Severe CD9:44–11:23

Lab work often reveals anemia, dehydration, and malnutrition, while imaging might show complications such as strictures, fistulas, and abscesses.
Alright, let’s break down stable severe CD into two categories; individuals with or without complications. First, if an individual presents with complications of CD, you should start them on IV fluids, begin empiric antibiotics, and consult surgery.
The surgeon will manage the complications by draining the abscess, performing a fistulotomy, or resecting the involved bowel.
After surgical intervention, reassess the severity to determine the appropriate treatment plan. On the other hand, if the individual presents without complications, you should start them on intravenous systemic corticosteroids, such as methylprednisolone, and a monoclonal antibody like infliximab.
Additionally, you can consider adding a thiopurine immunomodulator. If this achieves remission, taper off the corticosteroids, continue the current medical therapy, and follow up in 6-12 months.
In contrast, if this doesn’t achieve remission, continue the current medical therapy and consult surgery for possible resection of an affected segment.Alright, as a quick recap...

Review11:23–12:46

management of Crohn Disease starts with a history and physical, fecal calprotectin, stool studies, and labs that will point to IBD.
To confirm Crohn disease, you’ll need an ileocolonoscopy with biopsy. An MRE can also be helpful.
This will also help you determine severity and locate affected areas which guides management. For mild to moderate CD, right sided ileocecal disease needs corticosteroid as induction therapy while colonic disease should be treated with 5-ASA.
For moderate to severe, induction therapy is an oral systemic corticosteroid combined with a monoclonal antibody. An immunomodulator can be added if there’s no remission.
Finally, for severe, or fulminant UC, if they have complications, start them on antibiotics and IV fluid, then do a surgical consultation for appropriate treatment.
If there are no complications, induction therapy of CD includes IV systemic corticosteroids and a monoclonal antibody. You may need a surgical consult for resection if there’s no remission.
For all three severities, once CD is in remission, be sure to follow up with an ileocolonoscopy in 6-12 months.